ISLAMABAD — Taliban insurgents killed more than 20 Afghan government forces before overrunning a key police base in the western Farah province bordering Iran, military officials said.

An Afghan National Army (ANA) officer confirmed Tuesday the deadly assault occurred overnight in the Pasht-e-Ko district. He told VOA on condition of anonymity that authorities were still determining the exact number of casualties because hours-long fighting had disrupted telecommunication lines in the district.

A provincial council member, Dadullah Qani, told VOA that around 50 Afghan border police personnel were stationed at the base when it came under attack just before midnight on Monday.

A Taliban spokesman claimed its fighters killed more than 30 Afghan forces and captured 20 others along with heavy weaponry and ammunitions placed at the base.

Farah borders Iran and several of its districts are either controlled or hotly contested by the Taliban. Insurgent attacks in recent months have killed hundreds of police and ANA personnel in the sparsely populated province.

Last week an ANA helicopter crashed due to “bad weather” in the Taliban-held Anar Dara district, killing 25 people on board.

The deputy commander for western Afghanistan and the head of Farah’s provincial council were also among those killed.

Iran denies U.S. and Afghan allegations Tehran is militarily helping the Taliban to increase its influence in the western border provinces of Afghanistan. The Islamist insurgency came close to capturing the provincial capital of Farah in May this year.

Taliban refuses to deliver Afghan corpses

Insurgents maintain they shot down the helicopter and retrieved all the bodies from the site. The Taliban has already released about a dozen bodies to their relatives but it is refusing to deliver the remaining “enemy corpses” until the Afghan government hands over to relatives the body of the executor of last month’s high-profile attack in the southern city of Kandahar.

Taliban spokesman Zabihullah Mujahid told VOA on Tuesday that the swap demand had been conveyed to the Afghan government through the International Committee of the Red Cross (ICRC) but so far it has not been met. He rejected as propaganda official claims that the Taliban had received money from relatives before returning some of the bodies soon after the crash happened.

The Kandahar assault inside the highly secured governor’s compound in mid October killed revered Afghan commander General Abdul Raziq along with the provincial spy chief. The attack injured the U.S. military commander for operations in southern Afghanistan and two other Americans while the U.S. chief of international forces in Afghanistan escaped unhurt.

Deadliest Afghan election

Meanwhile, the United Nations has confirmed that insurgent attacks during three days of voting last month killed or wounded 435 Afghans, making the parliamentary elections the deadliest on record.

Most of the casualties, including 56 deaths, occurred on October 20, the opening day of voting, the U.N. Assistance Mission in Afghanistan (UNAMA) noted in its special reported released Tuesday.

“The Taliban’s actions forced many ordinary Afghans to choose between exercising their right to participate in the political process and risking their own safety,” the mission said.

The Islamist insurgency had denounced the polls as an “American orchestrated” plot to extend “foreign occupation” of Afghanistan and had called on its fighters to make all possible efforts to disrupt the election process.

But despite the threats and violence, Afghan election officials say that more than four million of the nearly nine million registered voters cast their ballots, though many alleged a significant number of the votes were based on fake identification documents. Moreover, security concerns had prevented Afghan authorities from opening 2,000 of the total more than 7,000 polling stations on the day of balloting.